This paper presents an ultra-wideband antenna formed with lumped elements series loading and parallel loading for indoor applications. Loaded with parallel and series resistors, the surface current of the antenna is distributed in the form of traveling wave, thereby effectively widening the impedance bandwidth of the antenna. The proposed antenna can operate over the whole band from 0.1 G to 3 GHz and maintains high efficiency throughout its whole frequency band. Moreover, the antenna has a compact structure of 310×270×0.8 mm 3 . Over the entire frequency range, it can obtain good omnidirectional radiation performance, gain and radiation efficiency. This paper presents and discusses the antenna design and experimental results in detail. With the ultrawideband property, the proposed antenna has the potential to be applied in electromagnetic field measurement, radio monitoring and visualization instruments.